自动增益控制电路——理论和设计

In the early years of radio circuits, fading (defined as slow variations in the amplitude of the received signals) required continuing adjustments in the receiver’s gain in order to maintain a relative constant output signal. Such situation led to the design of circuits, which primary ideal function was to maintain a constant signal level at the output, regardless of the signal’s variations at the input of the system. Originally, those circuits were described as automatic volume control circuits, a few years later they were generalized under the name of Automatic Gain Control (AGC) circuits [1,2].